Discussion of Background
Products in stick form, in particular lipstick, are typically packaged in devices of the type including a cup containing the formulation to be applied and capable, in response to an actuating command, of moving axially inside a sleeve between a storage position and an application position. The mechanism employed to actuate the axial displacement of the cup can take various forms. It can include a threaded rod below the cup engaging a nut, with the mechanism actuated by an operating element formed by a thumbwheel disposed under the sleeve. Alternatively, the mechanism can take the form of a helical ramp formed in a wall of the sleeve and in which a lug carried by the cup moves. Products in stick form, notably deodorant products, can be packaged in other types of devices incorporating a piston sliding inside a sleeve, such as that described, for example, in document U.S. Pat. No. 6,086,276. The piston can be actuated by a threaded rod engaging with a nut, or by a ratchet mechanism.
These types of mechanisms are relatively complicated to make and include a relatively large number of components.
Document FR 986 178 describes a casing for a lipstick in which the actuating mechanism is simplified. In particular, the casing includes a tube open at both ends in which a cup containing the lipstick is able to slide. The cup passes through the lower end of the tube in a manner such that the user can push it, causing the lipstick to move upwardly within the tube to emerge from the upper end. A closure cap is provided for attachment in a reversible manner on the tube. However, to ensure that the cap is sufficiently long to avoid crushing the lipstick if the cup is pushed down to its maximum extent when the housing is closed, the case must have a relatively large lengthwise dimension, equal to three times the length of the lipstick. In addition, because the cup carrying the product projects beyond the lower end of the tube, the product can be moved relative to the tube even when the case is in the closed position, which is not desirable particularly in the case of a creme stick.
Document EP0 503 324 describes a dispenser of the same type for dispensing a fluid product. The upper end of the tube is closed by a cap fixed on the tube and has a product outlet aperture which can be closed by a plug.
To reduce the size of such a casing, casings have already been proposed in which the cup is flush with the lower end of the tube. With such an arrangement, the user pushes the cup by the bottom of the tube to cause the product to emerge via the upper end of the tube. To apply the product, the user holds the tube and applies the solid product to the area desired. However, because the product is not fixed in relation to the tube, it is necessary for the cup to slide with sufficient friction on the inner wall of the tube so that the product does not recede back into the tube during application. However, if the friction is too great, the user has difficulty in pushing the cup inside the tube to cause the product to emerge before application.
Devices of the same type have been described in documents FR 1 524 080 and U.S. Pat. No. 3,443,874.